Conductor Sizing Calculators
Size conductors per NEC Table 310.16, derate for temperature and bundling, and verify voltage drop — all in one page.
3 Calculators NEC Table 310.16 Free to Use
Wire Size Calculator
NEC 310.16Determine the minimum conductor size for a given load, including automatic voltage drop verification at 3%.
Ampacity Derating Calculator
NEC 310.15Derate conductor ampacity for ambient temperature and conduit bundling per NEC 310.15(B) and 310.15(C).
Voltage Drop Calculator
NEC 210.19(A), 215.2(A)Calculate voltage drop for a circuit and verify it meets the NEC recommended 3% branch / 5% total limit.